Web folding assembly



United States Patent inventor Mnurito C. Blonibcrg Napervllle, Illinois Appl. No. 827,682 7 Filed May 26,1969- Patented Dec. 1, 1970 Assignee Mlehle-Goss-Dexter Incorporated WEB FOLDING ASSEMBLY 5 Claims, 6 Drawing Figs. US. Cl 270/86 lnt. B6511 45/22 Field of Search 270/86, 5,

References Cited UNITED STATES PATENTS 505,855 10/1893 Sheldon...

836,751 11/1906 Goss 270/86 1,982,703 12/1934 Strain 270/86 2,264,707 12/1941 Meyer 270/86 3,111,310 11/1963 Dutro et al.. 270/86 3,442,504 5/1969 Halley 270/86 Primary Examiner-Eugene R. Capozio Assistant Examiner- Lawrence R. Oremland Attorney-Wolfe, Hubbard, Leydig, Voit & Osann ABSTRACT: A generally triangular folder former having conical edges proportioned to avoid stressing a web being folded-and ending in a nose section curved to the new direction of web travel with rounded edges formed to continue the stress-free folding. Control of the web being folded is maintained by large diameter rollers fitted closely within the concave sides of the nose'section.

Z of 3 Shoat Patented I Dec. 1, 1970 Sheet- M Maw 417W WEB FOLDING ASSEMBLY DESCRIPTION OF THE INVENTION This invention relates generally to web folding devices and more particularly concerns formers for guiding traveling webs into a longitudinal fold.

Web fed printing presses normally include a number of printing units which direct the printed webs to a folder that superimposes a number of webs, folds the webs longitudinally down the middle, and severs the printed products. Often, the products are also folded transversely and stacked. Conventionally, webs are folded longitudinally by drawing them over a former structure that presents a pair of folding edges angled in from the web edges to a nose about which the paper folds.

Formers of this general description have been used for many years, but they have been a consistent source of operating difficulties. Rapidly running webs become creased, wrinkled or even torn when pulled over the formers. Such problems multiply when the number of superimposed webs is increased. The prior art tried many approaches to improve former operation, including rotating or frictionless folding edges, adjustable or floating nose pieces, and former shapes and configurations arrived at by guess and intuition. However, prior to the present invention, considerable empirical adjustment was usually required before any former performed acceptably, and even then operational defects were usually noted. Former design defects are often evidenced by heavy wear at certain areas of the former caused by the web straining against those areas instead of flowing smoothly about the former. Newsprint has been known to deeply groove steel formers in surprisingly short periods of time.

Accordingly, it is the primary aim of the present invention to provide an improved web folder which functions to guide webs into a longitudinally folded condition without uneven stresses being created in the web material. More particularly, it is an object of the invention to provide such a stress-free folder that avoids wrinkling, creasing and tearing of the web, and which also avoids ink'smearing or smudging resulting from superimposed webs being rubbed together during the folding process.

Another object is to providea folder assembly that creates a sharp fold line while maintaining full control of the web and without departing from the stress-free operation of the former.

A further object is to provide a folder as characterized above which, in addition to folding a broadsheet web, will handle a slip-apart pair of tabloid webs without lapping or spreading of the webs as they are superimposed.

Other objects and advantages will be apparent upon considering the following detailed description and upon reference to the drawings, in which:

FIG. 1 is a fragmentary vertical section of a portion of a printing press folder embodying the present invention;

FIG. 2 is an enlarged view of the former shown in the FIG. 1 folder;

FIG. 3 is a section taken approximately along the line 3-3 of FIG. 2;

FIG. 4 is an enlarged view taken approximately along the line 4-4 in FIG. 1;

FIG. 5 is a fragmentary side view of the structure shown in FIG. 4; and

FIG. 6 is a graph of the relationship between three angles.

While the invention will be described in connection with a preferred embodiment, it will be understood that I do not intend to limit the invention to that embodiment. On the contrary, I intend to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention.

Turning first to FIG. I, there is shown a web-folding assembly 10 which embodies the invention and is, for illustrative purposes, installed in a folder 11 intended to be utilized in a newspaper press. The folder 11 includes frame structures 12 and 13 supporting, at the top, a plurality of web-guiding rollers l4 and, beneath them, a set of driven folding and pressing rollers 15. A plurality of webs 20, in this case four webs of newsprint paper, are-led around the rollers 14, superimposed between a set of control rollers 21, and are folded double Ion gitudinally with the folded edge 22 being pressed between the folding rollers 15.

The folding assembly 10 operates to double the multilayer web 20 of material as it is pulled downwardly 1n the direction of an arrow 23 by the rollers 15, that direction being at an obtuse angle with respect to a plane 24 in which the web travels to the assembly 10. The edge 22 is, in effect, folded about a vertical fold line 25.

In carrying out the invention, the folding assembly 10 includes a generally triangular former 30 and a pair of relatively large diameter forming rollers '31. Preferably, the former 30 includes a pair of edge portions 32, a flat generally triangular portion in the form of a plate 33, and a nose section 34. The upper end of the former 30 is secured by posts 35 to a pair of arms 36, only one of which is shown, pivoted on the axis of one of the control rollers 21. The lower end of the former 30 carries a lug 37 to which a threaded rod 38 is pivoted. Nuts 39 on the rod 38 engage a collar 40 secured by a bracket 41 to the folder frame 12. It will be apparent that adjusting the nuts 39 permits setting the former 30 to precisely the designed angle of inclination 0 (see FIG. 1).

In accordance with the invention, the edge portions 32 define conical surfaces 46 having truncated cone apices pointing downstream of web travel with the center lines 56 of the conical surfaces defining a cone spread angle S (see FIG. 4), the conical surfaces 46 have a cone angle p, and the relationship between the angle of inclination 6, cone spread angle S and cone angle p being such to cause any transverse line in a web passing over the former to remain perpendicular throughout its length with respect to the fold line 25. The nose section 34 continues this conical and angular relationship and is formed with a generally triangular surface 47 interconnecting and smoothly continuing the truncated ends of the surfaces 46, the surface 47 being curved smoothly to an edge 48 parallel to and tangent with the fold line 25. The curved edge relationship is continued by the nose section 34 in that edges 49 of the nose section curve smoothly from the conical surfaces 46 with the edges 49 being curved on sharply decreasing radii as the triangular surface 47 bends toward the folded line so that any transverse line in a web passing over the nose section remains perpendicular throughout its length with respect to the fold line 25.

Before considering the relationship between the angles 0, S and p, it should be noted that the center-lines 56, if extended, intersect on the fold line 25. Similarly, the nose section edges 49 are defined by a family or generation of cones all of whose extended center lines, 56a and 56b for example (see FIG. 5), also intersect the fold line 25.

The proper relationship between the angles 0, S and p is shown in FIG. 6. As can be seen, these are not straight line or otherwise easily explained functions. Therefore, in the table following this paragraph, there is set forth for each half degree of angle of inclination 0 from 32.5 to 86.0 the proper cone spread angle S and cone angle 0-. Obviously, to practice the invention, an angle of. inclination 0 is selected based on the geometry of the folding assembly 11. This angle 0 establishes the angles S and 0' for the former 30. The shape of the nose section 34 is similarly developed as the angle of inclination increases to Cone Angle of inclination Spread angle Angle 37. 000000--. 24.321342 13. 974181 37. 500000 24. 417050 13. 839854 38. 000000- 24. 507920 13. 701941 38. 500000- 24. 593923 13. 560517 39. 000000 24. 675000 13. 415625 30. 500000. 24. 751093 13. 267309 40. 000000- 24. 822161 13. 115641 40. 500000. 24. 888154 12. 060687 41. 000000. 24. 949001 12. 802495 41. 500000- 25. 004651 12. 641139 42. 000000. 25. 055040 12. 476685 42. 500000. 25. 100121 12. 309220 43. 000000- 25. 139830 12. 138819 43. 500000. 25. 174000 11. 965547 44. 000000. 25. 202860 11. 789510 44. 500000- 25. 226053 11. 610777 45. 000000.-. 25. 243611 11. 429445 45.500000... 25. 255480 11. 245622 46.000000 25. 261571 11. 059387 46.500000 25. 261831 10. 870859 47.000000 25. 256190 10. 680140 47.500000 25. 244573 10. 487338 48.000000 25. 226920 10. 292573 48.500000 25. 203152 10. 005957 49.000000 25. 173210 9. 8976216 49.500000... 25. 137011 9. 6076794 50.000000. 25. 004501 9. 4962744 50.500000. 25. 045614 0. 2935379 51.000000. 24. 090271 9. 0896028 51.500000. 24. 928412 8. 8846116 52.000000. 24. 859961 8. 6787026 52.500000. 24. 784873 8. 4720373 53.000000. 24. 703070 8, 2647561 53.500000. 24. 614492 8. 057013 1 54000000-- 24. 519090 7. 8489721 54.500000. 24. 416701 7. 6407816 55.000000. 24. 307553 7. 4326146 55.500000 24. 191304 7. 2246212 56.000000.. 24.068001 7. 0169727 56500000-- 23. 937591 6. 8098347 57.000000. 23. 800040 6. 6033843 57.50000 23. 655281 6. 3977755 58.00000 23. 503281 6. 1931854 58.50000 23. 343991 5. 9897763 59000000.- 23. 177394 5. 7877319 59500000.. 23. 003441 5. 5872127 60.000000 22. 822100 5. 3883880 60500000-- 22. 633341 5. 1914220 61.000000-- 22. 437152 4. 9964891 61500000-. 22. 233511 4. 8037534 62000000.. 22. 022893 4. 6133741 62500000.- 21. 803781 4. 4255086 63000000.- 21. 577673 4. 2403194 63.500000.. 21.344060 4. 0579568 64.000000 21. 102942 3. 8785746 64500000.- 20. 854325 3. 7023187 65000000.- 20. 598210 3. 5293272 65500000.- 20. 334612 3. 3597418 66000000-- 20. 063551 3. 1936030 66.500000 19. 785042 3. 0313071 67.000000 19. 499111 2. 8727040 67.500000-- 19. 205802 2. 7180024 68000000.. 18. 905133 2. 5673034 68.500000 18. 597161 2. 4207147 69.000000.- 18. 281931 2. 2783264 69.500000" 17. 959501 2 1402286 70000000.. 17. 629912 2 0064934 70500000-- 17. 293251 1. 8771977 71.000000... a 16. 949561 1. 7523948 71.500000. 16. 598961 1. 6321500 72.000000. 16. 241492 1. 5164950 72500000.. 15. 877261 1. 4054722 73000000-. 15. 506372 1. 2991069 73.500000... 15. 128910 1 1974122 74.000000.. 14. 744991 1 1003962 74.500000. 14. 354721 1. 0080541 75000000. 13. 958231 92037520 75500000-. 13. 555641 83733362 76.000000. 13. 147091 75889776 76.500000... 12. 732701 68502202 77.000000. 12. 312642 61565666 77.500000.. 11. 887044 55073349 78.000000 11. 456082 49018263 78.500000 11. 019902 43391840 70.000000 10. 578682 38184720 79500000.. 10. 132602 33386846 80000000.. 9. 6818260 28986656 80.500000.. 9. 2265420 24972147 81.000000" 8. 7669620 21330256 81.500000.. 8. 3032620 18047018 82.000000" 7. 8356420 15107424 81500000.. 7. 3643040 12495957 83000000.. 6. 8894820 10196345 83.500000. 6. 4113750 8. 1911706E-02 84.000000 5. 9301700 6. 4625570E-02 84.500000. 5. 4461550 4. 9921181E'02 85000000.. 4. 9594650 3. 7603735E-02 85.500000... 4. 4704050 2. 7477852E-02 86.000000 3. 9792250 1. 9340133E-02 As a feature of the invention, the plate 33 is set in notches formed in the conical surfaces of the edge portions 32 (see FIG. 3), and the notches are slightly offset laterally from planes running vertically through the center lines 56 so that the top surface 45 of the plate 33 is slightly below a plane tangent to both of the surfaces 46. This provides a clearance, preferably on the order of five one-thousandths of an inch, between a web being pulled over the former and the surface 45 of the plate 33. This clearance minimizes the possibility of ink smearing when a printed web is being folded and, more important, the web does not contact a ridge or sharp edge at the juncture of the plate 33 and the edge portions 32 which could scrape or tear the web material. Thus, while the plate 33 does not actually engage a taut web, the plate does serve to hold the edge portions 32 in rigid, proper alinement.

To understand the significence of the conical surfaces 46 and of keeping transverse lines perpendicular to the fold line 25, it should first be noted that a transverse line such as the line 51 (see FIG. 1) which is straight and thus perpendicular throughout its length with respect to the line 25 means that there is no twisting stress at that portion of the web defining the line 51. If all lines transverse of the web 20, like line 52 at the start of the folding operation and line 53 midway through the fold, also remain perpendicular throughout their length to the arrow 23, including those portions of the lines over the surfaces 45 and 47, then the entire web can be seen to remain stress free during the folding operation.

Transverse web lines like the lines 51,52 and 53 will remain perpendicular throughout their length to the line 25 if the surfaces 46 are truly conical, if the cone center lines intersect the line 25, and if the cone angle and the cone spread angle are properly proportioned to the former angle of inclination. lt has been found that for any one angle of inclination, there is one cone angle and one cone spread angle that will keep a transverse line perpendicular to the line 25. A former which is not as sharply inclined as the former 30 will require conical edges ofa larger conical angle than the surfaces 46. Conversely. as the angle of inclination approaches the web travel direction, i.e., the direction of the arrow 23, the proper cone angle becomes less and less. Hence, when forming the nose section 34, the edges 49 are formed with sharply decreasing radii to maintain the proper relationship as the nose section bends toward the edge 48.

A former properly shaped in the manner of the former 30 completely fills the natural volume and is coextensive with the area and linear dimensions of the web as the web is folded. Therefore, there is no wrinkling or stretching of the web, and the web smoothly contacts the former.

With the configuration described, the web lies flat on the former 30 with no stresses to cause wrinkles or tears. Multiplelayer webs run smoothly without relative sliding, which can cause ink smearing. The nose section edge 48 defines a sharp fold 22 and, as a result of the configuration of the edges 49, the nose section has concave sides into which are closely fitted the peripheries of the rollers 31 (see FIG. 4). There is, there fore, a substantial region of close spacing between the large diameter rollers 31 and the sides of the nose section 34. This gives good control of the web at the fold line.

Because of the stress free handling of the web by the assembly 11, tabloid-sized webs formed by splitting a broadsheet web are handled with no lapping or spreading of the narrower webs as they are curved over the former 30 into superimposed relation.

lclaim:

l. A folder former for doubling a web of material about a straight fold line when the web is pulled from one plane over the former in a direction parallel to said fold line and at an obtuse angle with respect to the plane, in which the former includes edge portions defining conical surfaces having truncated cone apeces pointing downstream of web travel, said edge portions being angled so that the center lines of said conical surfaces would, if extended, intersect on said fold line, said conical surfaces having a cone angle, cone spread angle and angle of inclination causing any transverse line in a web passing over the former to remain perpendicular throughout its length with respect to said fold line, said former also including a nose section defining a generally triangular surface interconnecting and smoothly continuing the truncated ends of said conical surfaces, said nose section triangular surface being curved smoothly to an edge parallel to and tangent with said fold line, said nose section having edges curving smoothly from said conical surfaces and said triangular surface, said edges being curved on sharply decreasing radii as the triangular surface bends toward the fold line so that any transverse line in a web passing over the nose section remains perpendicular throughout its length with respect to said fold line.

2. The former of claim 1 in which said cone angle, cone spread angle and angle of inclination have the relationships set forth by FIG. 6 of the accompanying drawings.

3. The former of claim 1 in combination with a pair of forming rollers disposed perpendicular to said fold line and parallel to one another in cooperating relationship on either side of said nose section edge, said rollers being of sufficient diameter to enable the roller peripheries to follow closely the concave sides ofsaid nose section formed by the curved edge portions.

4. The former of claim 1 in which said nose section edges are defined by a family ofcones all ofwhose center lines, if extended, would intersect said fold linev 5. The former of claim 1 including a flat, triangular portion interconnecting said edge portions and being set below a plane tangent to said edge portions. 

